Project Summary/Abstract (30 lines max) Surgery often has benefits, such as reducing symptoms or extending life, but it is not without risk. Patients vary both in their tolerance of symptoms and of surgical risk. The concept of shared, patient preference-concordant surgical decision making potentially helps patients achieve their goals. Surgical decision-making for persons living with dementia (PLWD) is challenging for numerous reasons, including limited longitudinal data on outcomes, an inability of the patient to fully participate in the discussion, and vague advance directives with multiple caregivers(surrogates). In the absence of evidence-based guidelines, clinicians struggle with recommendations and patients and caregivers face uncertainty about the consequences of surgery. Research on dementia and surgery is limited. However, our pilot work has found that among common vascular procedures, PLWD had poorer surgical outcomes compared with persons w/o dementia. In other pilot work exploring the use of Advance Care Planning among PLWD facing surgery, we are finding that surgeons do not routinely consider dementia as an independent risk factor. A stronger evidence base has the potential to facilitate surgical decision-making. The proposed mixed methods study is designed to understand the epidemiology of surgery for PLWD, as well as patient, caregiver, and provider practices and challenges of surgical decision- making in clinical settings. We focus on surgery because it is common among elderly PLWD, it often represents a critical inflection point in quality of life, and therefore is a fraught process for all involved. The goal of the study is to improve decision-making and enhance recovery when surgery is chosen. Aim 1) Develop the evidence base to understand the case mix and comparative outcomes of surgery provided to PLWDs. We will use large databases to describe the epidemiology of inpatient surgery for PLWD from several perspectives intended to inform expectations and decision-making. Case identification of dementia will take advantage of state-of-the-art methods from an ongoing R01. Aim 2) Characterize surgical decision-making for PLWD in practice settings, as perceived by PLWD and their family caregivers, and providers/clinicians. Using case studies of a multi- regional selection of 12 health systems, we will explore in-depth: 1) Approaches to surgical decision- making for PLWDs; 2) Priorities and unmet needs of patients, families, and surgeons around surgical decision-making; 3) Facilitators and barriers to making patient preference-concordant care decisions. Aim 3) Develop recommendations around surgical decision-making processes. We will conduct a modified Delphi panel with national experts and stakeholders to develop recommendations about surgical and non-surgical options that mitigate the unique vulnerabilities of PLWD.